The present disclosure relates generally to desalination systems and methods. More particularly, this disclosure relates to desalination systems and methods using membrane distillation and a novel configuration including vapor compression, membranes and heat transfer surfaces.
Less than one percent of water on the earth's surface is suitable as an eligible water source for direct consumption in domestic or industrial applications. In view of the limited eligible water sources, de-ionization or desaltification of wastewater, seawater or brackish water, commonly known as desalination, becomes an option to produce fresh water.
Different desalination processes, such as distillation, vaporization, reverse osmosis, and partial freezing are currently employed to de-ionize or desalt a water source. Of particular interest is membrane distillation as an emerging technology. Membrane distillation (MD) has the potential to compete with conventional thermal desalination processes. To date the common configurations of membrane distillation are direct contact MD, air gap MD, and vacuum MD. In order for MD to make efficient use of energy, the latent heat of condensation of the distillate must be recovered and recycled into the process. In all known implementations of these MD configurations, the recovery of the latent heat of condensation has been through absorption by a liquid water stream in the form of sensible heat. The liquid is subsequently exposed to an MD membrane to allow vaporization. Such processes can suffer from low efficiency and low recovery of distillate from the feed water due to the need for a high flow rate of liquid mass relative to the produced distillate and high-energy consumption, which may prohibit them from being widely implemented.
Therefore, there is a need for a new and improved desalination system and method for desalination using membrane distillation.